In the handling and packaging of containers such as cans, it is common to use a carrier having an array of openings therein for receiving the upper ends of the cans and holding an array of cans to form a container package. Typical United States patents showing such a carrier are U.S. Pat. Nos. 3,874,502, 4,219,117 and 4,586,742.
Such a carrier comprises an interconnected series of bands or rings which are non-circular and which is applied by lateral stretching by machine which inserts fingers into the openings to stretch the openings to a generally circular configuration and then the carrier is forced onto the upper end of the cans below the chime or bead on the cans. During the stretching and application, the bands are folded downwardly along the peripheral surface of the necks of the cans. The resultant package comprises a plurality or array of cans surrounded by the stretch plastic rings.
In pending application Ser. No. 319,775, filed Mar 7, 1989, now U.S. Pat. No. 4,911,290, issued 3/27/90, having a common assignee with the present application, the container package comprises an array of cans and a carrier. The carrier includes a sheet of stiff but flexible plastic material having a plurality of openings forming an array for receiving the ends of the cans and a film of plastic material coextensive with the sheet and bonded to the periphery of the sheet so that it is flat and taut on the sheet. The cans are inserted upwardly into the openings and retained by the carrier by flexing of the periphery of each opening upwardly against the chime or bead of each can. As the cans are inserted, the film is stretched taut over the upper ends of the cans. The film is stretched substantially flat and taut from one peripheral edge to an opposite peripheral edge. The carrier thus protects the cans from contaminants. The carrier supports the array of the cans so that the upper ends of the cans are in a single plane when the package is lifted through finger openings in the film and sheet. The film and sheet define a substantially flat planar upper surface. Indicia such as printing, advertising, logos, artwork and other markings are provided on the film, preferably on the entire surface of the film.
In pending application Ser. No. 385,635, filed July 26, 1989, now U.S. Pat. No. 4,915,217, issued 4/10/90, having a common assignee with the present invention, the container package for cans embodying the invention comprises a sheet of flexible plastic material having a plurality of openings for receiving the upper ends of the cans, the cans extending upwardly through the openings in the sheet with the periphery of the openings flexing upwardly and inwardly beneath the bead of the cans. The modulus of elasticity of the sheet, the thickness of the sheet, and the spacing and size of the openings is such that the bodies of the cans are maintained in abutting relationship, with the plane of the sheet remaining substantially undisturbed and the upper ends of the cans being maintained in substantially the same plane when the package is lifted by engaging the carrier.
Among the objectives of the present invention are to provide a method and apparatus for applying carriers of the types defined in the aforementioned applications Ser. No. 319,775 and Ser. No. 385,635 at high speeds, efficiently and without damaging the carriers or the containers. The disclosure of these applications is incorporated by reference thereto into this application.
In accordance with the invention, the method and apparatus of applying carriers to arrays of containers comprises providing a web of interconnected plastic carriers, each carrier having an array of circular openings for receiving the upper ends of the containers, the diameter of the openings being slightly less than the cross section of the upper ends of the containers. With a plurality of containers, where each container has a bead, a neck and a body portion, the cans are moved in a predetermined path and the web is moved in a converging path with respect to the direction of movement of the containers. The movement of the cans is such that the trailing edges of the beads of each transverse row of containers engages the trailing edges of a corresponding row of openings in a carrier due to the relative movement of each row of cans relative to the respective row of openings in the carrier. Continued convergence will cause the leading and side edges of the row of openings of a carrier to pass over the leading and side edges of the beads of the cans. Likewise, by successively engaging succeeding rows of containers with succeeding rows of openings in the carrier, an array of containers in the carrier is formed, and thereafter severing each carrier from the remainder of the web will provide a package having a predetermined array of containers.